Pushbutton combination lock



June 3, 1969 YOICHI KAWAMURA 3,447,347

PUSHBUTTON COMBINATION LOCK Sheet Filed NOV. 28, 1967 FlG.7b

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June 3, 1969 YOICHI KAWAMURA 3,447,347

PUSHBUTTON COMBINATION LOCK Filed Nov. 28, 1967 Sheet 8 of 3 FIG. 2

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June 3, 1969 YOICHI KAWAMURA 3,447,347

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United States Patent 3,447,347 PUSHBUTTON COMBINATION LOCK Yoichi Kawamura, 171 Nishikubo-cho, Hodogaya-ku, Yokohama-ski, Kanagawa-ken, Japan Filed Nov. 28, 1967, Ser. No. 686,012 Claims priority, application Japan, Nov. 30, 1966,

41/ 78,571 Int. Cl. G05g 5/04; E05b 37/00, 63/20 US. Cl. 70213 6 Claims ABSTRACT OF THE DISCLOSURE This invention relates generally to locks for doors and the like and more particularly to a new pushbutton combination lock with changeable combination.

The object of a key-operated lock is to prevent persons other than those possessing the applicable key and duplicate or spare keys from opening the lock. Accordingly, a large number of duplicate keys is undesirable, but a limitation of the number of duplicate keys causes great inconvenience in such instances as that when a large number of selected persons are to use at respectively dilferent times a room which is ordinarily locked and can be unlocked only by said keys. Furthermore, key-operated-locks can be picked or unlocked with master keys or-passkeys in undesirable hands. In such circumstances, a simple combination lock is preferable, but in conventional combination locks, the combination cannot be readily changed.

It is an object of the present invention to overcome such difiiculties associated with known key-operated and combination locks. More specifically, an object of the invention is to provide a pushbutton combination lock which, on the exterior side thereof, can be unlocked merely by and only by manipulating specified push buttons in a specified sequence, and in which the combination of pushbutton numerals and manipulating sequence can be readily changed. 1

Another object of the invention is to provide, in a lock of the above stated character, a device whereby the state of the unlocking combination mechanism can be cleared or returned to the original state when the push buttons have been erroneously pushed and a device for holding the lock bolt in unlocked position.

A further object of the invention is to provide a lock of the above stated character which is completely installed in a compact arrangement within three blocks, two of which may be adapted to constitute, respectively, the exterior and interior door knobs of a door.

According to the present invention, briefly summarized, there is provided a push-button combination lock characterized by the combination of a first block containing an unlocking tube actuating mechanism in which, only when specified pushbuttons are manipulated in a specified sequence in accordance with a preset combination, the unlocking tube is caused to undergo a rotational displacement of a specific angle in a given or constant direction, a second block containing a bolt actuating mechanism operating in accordance with said displacement of the un- 3,447,347 Patented June 3, 1969 locking tube to unlock a lock bolt, and a third block containing a combination setting and changing mechanism for changeably setting the combination of said specified push buttons in a specified sequence.

The nature, principle, details, and utility of the invention will be more clearly apparent from the following detailed description with respect to a preferred embodiment of the invention when read in conjunction with the accompanying drawings, in which like parts are designated by like reference numerals and characters.

In the drawings:

FIG. 1 is a front elevation view, as viewed from the doorway frame side, showing the external parts of one example of a door lock constituting an embodiment of the invention;

FIG. 2 is an exploded perspective view, with parts cut away, showing essential parts of the door lock shown in FIG. 1;

FIG. 3 is a partial plan view, in horizontal section, showing parts of the knob of the door lock on the exterior side of the door;

FIG. 4 is a sectional view taken in the plane designated by line IV-IV in FIG. 3;

FIG. 5 is a side elevation view, with parts in section, showing the lock bolt actuating block of the door lock;

FIG. 6 is a plan view, with a part cut away and parts in section, showing parts of the door knob on the interior side of the door; and

FIGS. 7a and 7b are views in the axial direction of the lock mechanism showing parts in difierent positions for a description of the operation of the lock.

For standardization of terms relating to directions throughout the present disclosure, the terms exterior and interior are used respectively to designate directions from an inner part of a lock toward the exterior and interior sides of the door or the like in which the lock is installed. The terms front and rear respectively designate directions, as viewed from the look, toward and away from the doorway frame or jamb.

Referring to the drawings, the entire door lock assembly M is made up of three functional blocks, namely, an unlocking tube actuating block A provided internally therewith with an unlocking tube actuating mechanism a, a lock bolt actuating block B provided internally therewithin with a lock bolt actuating mechanism b, and an unlocking combination changing block C provided internally therewithin with an unlocking combination changing mechanism 0.

The mechanisms a, b and c are coaxially alined on the axis of a horizontal unlocking tube 3. The external structure of block A is an exterior door knob 23a on the exterior side of the structure 24, such as a door, on which the lock M is mounted, while the external structure of Block C is an interior door knob 230 on the interior side. The block B is a mortise lock imbedded in the door and disposed between blocks A and C, the entire lock assembly M being secured to the door 24 by screws passed through holes 25 in the front plate of the block B. The unlocking tube 3 is supported upon an axially extended support shaft 3a (FIG. 6) which extends from the combination changing mechanism c portion of the lock within the interior of the inner knob, and extends axially through the lock assembly to the casing 2a at the op-- posite side within the outer knob.

The unlocking tube actuating mechanism a is housed within a casing 2a and is provided with an intermittent drive assembly 16 (FIGS. 2 and 7a) in which one end of the aforementioned unlocking tube 3, which extends fully between the knobs, is rotatably supported in a bearing at the center of an exterior end wall of the casing 2a. A coil spring 4a is installed in an arcuate chamber at the radially outer side of the assembly 1 so as to impart constantly a torque in one direction to the unlocking tube 3. On the inside, a ratchet wheel 5 is fixed integrally and coaxially with the unlocking tube 3, and a toothed unlocking disk 6 is fixed coaxially to the tube 3 near the exterior end theerof. A ratchet pawl 7 is pivoted on the inner wall of the casing 2a and is normally engaged with the ratchet wheel 5.

The unlocking tube actuating mechanism a is further provided with a ratchet drive assembly 8, in which a sleeve 9 is loosely fitted around the unlocking tube 3 between the ratchet wheel 5 and toothed unlocking disk 6. The sleeve 9 is provided at its exterior and interior ends respectively with a toothed ratchet drive disk 10 and a pawl actuating cam plate 11 fixed thereto. A spring 12 is installed between the base or proximal part of the cam plate 11 and the casing 2a to impart constantly a returning force to the ratchet drive assembly 8. A stop projection (not shown) is provided on the exterior wall of the casing 2a to prevent excessive rotation of the cam plate 11.

A lock bolt 14 of approximately rectangular shape is slidably fitted in a bolt hole 15 formed in the lower part of the front wall plate of lock bolt actuating block B. A tension spring 16 is stretched between the rear end of the bolt 14 and a stud pin fixed to the inner wall of the block B to impart constantly at retracting force to the bolt 14.

To the rear of the bolt 14, an unlocking lever 17 is pivoted on a pivot pin 18 passing through approximately the middle part thereof, and the front end of this lever 17 nearest the bolt 14 is subjected constantly to a downward force by a spring 19. The unlocking lever 17 is actuatable by the distal end of an unlocking arm 20 fixed to and rotating with the unlocking tube 3, the distal end being adapted to press against the upper surface of the rear part of the unlocking lever 17.

A locking arm 21 is rigidly fixed to a locking sleeve 22 loosely and rotatably fitted around the unlocking tube 3 in a position such that, when the interior door knob 230, or exterior door knob 23a, is appropriately rotated,

the locking arm 21 is rotated, and its distal end presses forward against the rear end of a bracket 14a fixed to and extending rearward from the lock bolt 14 to force the bolt 14 forward against the force of the spring 16 until the bolt is cocked and held in the locking position by the front end of the cocking lever 17, whereby the lock is locked. It is to be noted that locking sleeve 22 also extends between the interior and exterior door knobs, but is of composite form and includes an interior portion having an interlocking detent 22a (FIG. 2) for fitting within complementally formed recess 22b on the medialto-exterior portion of said sleeve.

The exterior door knob 23a has a shape similar to that of a cup with a raised bottom and is secured at its rim to the outer periphery of the casing 2a at the exterior end thereof. The raised bottom, which forms a recessed wall in the installed door knob 23a, is provided with a plurality of holes arranged on a circle around the door knob axis and holding respective push buttons 26 loosely and slidably inserted in the holes.

Each push button 26 is connected at its interior or root end to an unlocking pin 27 directed toward the interior and having an inclined surface 270 at the interior extremity thereof. Each push button 26 has a hollow interior 30 accommodating the exterior end of a compression spring 28, the interior end of which abuts against a stepped shoulder for-med in the inner wall of the door knob 23a. The spring 28 exerts constantly a force on the push button toward the exterior. The unlocking pins 27 extend toward the interior and into the casing 2a through respective holes 31 formed in the exterior wall of the casing 2a.

A clearing or nullification ring 32 is loosely fitted around the outer periphery of the casing 2a and is provided at a p c fic position on its inn r surface with a recess 33 for operating as a cam. The function of this nullification ring 32 is as follows. When an error has been made in the sequence in which the push buttons 26 are pushed, the ratchet wheel 5 can be caused to return to its original position by rotating the nullification ring 32, the recess 33 and inner surface of the ring 33 thereby actuating the pawl 7 to disengage the pawl from the ratchet wheel 5 (see FIG. 7a).

The interior door knob 230 is fitted on and fastened to the interior end of a casing 2c of the block C. An unlocking ring 34 is loosely fitted around the casing 20 on the exterior side of the interior door knob 23c and is coupled to the unlocking tube 3 by a connecting member 35.

When the lock is to be unlocked from the interior side, unlocking ring 34 is rotated, whereby connecting member 35 transmits the rotation to cause unlocking tube 3 to rotate. Consequently, unlocking arm 20 fixed to unlocking tube 3 operates to cause unlocking lever 17 to rotate about its pivot 18 and release lock bolt 14, which thereupon is pulled by the force of spring 1 6 to retract into the unlocked position.

The unlocking ring 34 houses a locking arm holding device 36 for holding the locking arm 21 and preventing it from moving the lock bolt 14 into locking position even when the door knobs 23a and 230 are turned. This holding device 36 comprises an annular surface cam 37 projecting laterally toward the central portion of the lock and fitted within the unlocking ring 34 but extending less than the full annular distance of said ring 34. It further comprises, a slide pin 38 for slidably following the cam 37, a spring 39 for urging the slide pin 38 constantly toward the cam 37, and a locking plate 40 fixed to the interior end of the locking sleeve 22 and provided at specific positions near its periphery with a hole 41.

The locking arm holding device 36 operates in the following manner. When unlocking ring 34 is turned to the extreme limit of its rotation, annular surface cam 37 rotates together therewith, and the annular surface of cam 37 presses slide pin 38. Slide pin 38 thereupon moves toward the interior, and its inner end fits into hole 41 in locking plate 40. Consequently, locking plate 40 is prevented from rotating, and door knobs 23a and 230 no longer rotate, whereby the intended purpose of the device 36 is achieved. When the ring 34 is rotated in the reverse direction, pin 38 is retracted from the hole 41 along the inclined cam surface 37 by means of the force of the spring 39, whereby it returns to its original positi0n.'

The unlocking combination changing mechanism c (FIGS. 2 and 6) within block C is provided for the purpose of changing the unlocking combination code, that is, the sequence in which the push buttons 26 must be pushed to unlock the lock, and has the following organization. A combination numeral and sequence setting disk 42 is fixed at its center to the interior end of the unlocking tube 3 and is provided near its peripheral edge with a plurality of small holes 43 circu-mferentially spaced in a circle. An actuating member 44 having pins 45 fixed perpendicular thereto at the ends thereof is disposed'on the interior side of the disk 42 coaxially therewith and fixed at its center to the exterior end of an actuating rod 46, the pins being normally engaged in preset holes 43. The actuating rod 46 supports a numeral indicating disk 47 fixed thereto and extends through the interior wall of the interior door knob 230, being provided at its interior extremity with a button 48 fixed thereto. A window portion 49 is formed in the interior wall of the door knob 23c to permit observation of numerals on the numeral indicating disk 47.

The unlocking combination changing mechanism 0 of the above described organization operates in the following manner when an unlocking combination is changed. As the numeral indicating disk 47 is observed through the window 49, the button 48 is pulled to extract the pins 45 of the actuating member 44 from the originally set holes 43 of the numeral changing disk 42. The button 48 is then turned to the position of a desired numeral as indicated on the disk 47. This rotation causes the unlocking tube 3 to rotate, whereby the toothed unlocking disk 6 fixed to the tube 3 rotates. Accordingly, the positional relationship between the unlocking disk 6 and the ratchet drive disk 10 is changed. In this manner the desired change in the unlocking sequence is achieved.

A click latch 50 (FIG. 5) is further installed at the front part of block B and is provided with a spring 51. While this latch 50 and spring 51 are not essential parts of the invention, they are nevertheless convenient for holding the door in closed state when the lock bolt 14 is in retracted state and for centering the lock for locking.

In the example of the unlocking operations as illustrated in FIGS. 7a and 7b, the lock is to be released by the push-buttons 26 being pushed in the sequence of -5-8-3. The radially extending teeth of the unlocking disc 6 are lagged in angular position by 9, 18, and 27 degrees, respectively, from the positions of the teeth corresponding to the numerals 5, 8 and 3 of the ratchet drive disc 10.

By this arrangement, when a pushbutton 26 of a specified numeral is pushed (in this example, the pushbutton 0 at which the tooth of the unlocking disc 6 and the tooth of the ratchet drive disc 10 corresponding to the numeral 20 are coincided) the aforementioned inclined surface 27a at the extremity of the corresponding unlocking pin 27 causes the unlocking disc 6 and the ratchet drive disc 10 to undergo a rotation of 16 degrees (this rotational angle of the discs may be set selectively in accordance with the number of the push-buttons to be preset; in this case, the pushbuttons are to be preset four times), and, accordingly, the ratchet wheel and cam plate 11 also rotate together through 16 degrees.

When the pushing force on the abovementioned pushbutton 26 is removed, the unlocking disc 6, the natchet drive disc 10, the cam plate 11, and the ratchet wheel 5, respectively, begin to rotate in the reverse direction. However, when a return rotation of 7 degrees has been made, the pawl 7 is caused to engage with the ratchet wheel 5 by the action of the cam surface of the cam plate 11, whereby the reverse rotation of the ratchet wheel 5 is fully stopped. Accordingly, the unlocking disc 6 stops with resultant angular displacement of 9 degrees, which is the diiference caused by the initial rotation of 16 degrees and the reverse rotation of 7 degrees, and the ratchet drive disc returns to its original position.

Then, when the succeeding push button 26 of specified numeral is pushed, unlocking disk 6 is rotated through an additional 9 degrees in a manner similar to that described above. Similarly, the succeeding pushbuttons 26 of specified numerals are pushed in sequence to rotate unlocking disk 6 through a predetermined angle, thereby causing unlocking arm 20 to press down on the rear end of unlocking lever 17, whereby lock bolt 14 is released and retracts into unlocked position.

If an error is made in the sequence in which pushbuttons 26 are pushed, and a button of a numeral other than the specified numeral is inadvertently pushed, the lock cannot be unlocked. In such a case, the nullification ring 32 is rotated to return the mechanism to the normal locked state as described hereinbefore, and the manipulation of the push buttons 26 is carried out anew from the beginning.

A further feature of the lock of the present invention is that the numerical code or combination of pushbutton numerals and sequence can be readily changed and reset by suitably rotating the combination changing disk 42 by means of the button 48 as described hereinbefore.

Accordingly, the present invention provides a convenient lock for locking the doors of rooms, compartments, and enclosures which are to be kept closed when not in use but are to be opened a difierent times by a large number of specific persons.

What I claim is:

1. A pushbutton combination lock having a supporting 6 shaft (3a), and an exterior (A) and interior (C) knob, each knob having end faces, and said knobs operatively attached at opposite ends of said supporting shaft, comprising in combination:

(a) an unlocking sleeve (3) rotatably set on said support shaft (3a), one end of said unlocking sleeve (3) being directly connected to the exterior knob (A), said unlocking sleeve (3) extending through to the interior side of the lock and being operatively and indirectly connected with the interior knob (C);

(b) a locking sleeve (22) rotatably fitted around said unlocking sleeve (3);

(c) a plurality of pushbuttons (26) arranged in a circular form around the end face of the exterior knob (A);

(d) a lock housing (B) disposed intermediate the exterior and interior knobs with the plane thereof coplanar with the plane of the door with which it is associated, said housing (B) including a face plate portion adapted to be mounted flush with the edge of said door, said lock housing including a transversely shiftable lock bolt (14) mounted therein cooperatively with a complemental aperture (15) formed in said face plate thereof;

(e) locking means (21) including disc means operatively rotatable by the respective knobs and fixed to the locking sleeve (22) and operatively connected (14a) with said lock bolt (14) to cause said lock bolt to be projected forward and means (17-19) maintaining it in a locked condition, and means (16) resiliently pulling on said bolt (14) to return it to its unlocked condition when the means (21, 17, 19) biasing it in its locked condition are released;

(f) unlocking means (3-11, 17, 20, 26) movable in a single given direction of rotation due to presetting of the pushbuttons (2-6) in a predetermined sequence, thereby causing said lock bolt (14) to return to its unlocked condition; and

(g) manually operated means (44-49) to change the combination of the unlocking code, said means being axially shiftable and correspondingly aligned and operatively connected with said unlocking sleeve (3).

2. A pushbutton combination lock according to claim 1 in which the unlocking means comprise:

(a) a pivotally mounted ratchet pawl (7);

(b) a tooth unlocking disc (6) and a ratchet wheel (5) with which said pawl (7) is selectively engageable, both being fixed integrally and coaxially spaced upon and with said unlocking sleeve (3);

(c) a toothed ratchet drive disc (10) and a cam plate (11) to actuate said ratchet pawl (7), both being fitted at both ends of a sleeve loosely encircling said unlocking sleeve (3) and disposed between the toothed unlocking disc (6) and the ratchet wheel (5); and

(d) a casing (2a) to accommodate the entire locking means therewithin, said casing having an exteriorly facing end wall provided with a plurality of apertures (31) disposed in a circular arrangement to permit passage of the knob-mounted pushbuttons (26) when pressed therethrough and projected into said housing, said buttons (26) coacting with said toothedunlocking disc (6) to cause the unlocking means to rotate.

3. A pushbutton combination lock according to claim 1 in which the locking means comprises: a lock bolt slidably held in a housing; a bracket fixed to and extending rearward from the lock bolt; a spring to impart constant retracting force to the bolt; a locking arm having a radially extended distal end coaxially fixed to the locking sleeve to rotate therewith, the distal end of the locking arm pressing forward the rear end of the bracket to cock the lock bolt and hold it in the locking position; a locking and unlocking lever pivotally fitted on one portion of the housing and to engage the lock bolt in a locking position and to disengage the same from the locking position; and an unlocking arm having a distal end fixed to and rotating with the unlocking sleeve, the distal end of which presses against the upper surface of one part of the lever, whereby, when the internal or external knobs are rotated, the locking arm presses forward the lock bolt to its locking position and the lever securely holds the lock bolt in the locking position, and, when the unlocking means is operated by the presetting of the pushbuton in the predetermined sequence, the unlocking arm gradually and progressively rotates in the direction to push the lever to disengage the lock bolt from its locking position.

4. A pushbutton combination lock according to claim 1 in which the manually operated means to change the combination of the unlocking code comprises: a combination numeral and sequence setting disc fixed at the center thereof to the extreme end of the unlocking sleeve (3) and provided with a plurality of small perforations near the peripheral edge thereof in a circular arrangement; an actuating member having a plurality of pins fixed perpendicularly thereto at the radial ends thereof, said pins being normally engaged in the perforations provided in said combination numeral-and-sequence setting disc; and an actuating rod attached at one end thereof to the center of the actuating member, and means for rotatably and slidably supporting it for axial shifting directions coaxial with the interior knob and the unlocking sleeve.

5. A pushbutton combination lock according to claim 2 in which there is further provided a nullification device for returning the ratchet wheel to the original position thereof when the pushbuttons are pushed in erroneous sequence, the device comprising a ring rotatably fitted around the outer periphery of the casing and a recess provided on the inner surface of the ring to operate as a cam to selectively disengage the pawl from the ratchet wheel.

6. A pushbutton combination lock according to claim 3 in which there is further provided a locking arm holding device comprising a ring rotatably fitted around the casing adjacent to the inner end of the internal knob for unlocking the combination code changing means, an annual cam having a laterally directed cam surface provided in the inner surface of said ring, a slide pin, a spring for urging the slide pin constantly toward the cam, and a locking plate fixed to one end of the locking sleeve and provided with a perforation at a specific position near the periphery thereof and in alignment with the slide pin to receive the slide pin when it is pressed forward thereinto by the action of the cam, and a connecting member to couple together the ring and the unlocking sleeve.

References Cited UNITED STATES PATENTS 6/1953 Gifim 70-313 9/ 1966 Traversa et al 70-288 US. Cl. X.R. 

